Brinell hardness testing device



y 8, 1945- J. o. BISHOP ETAL 2,375,341

BRINELL HARDNESS TESTING DEVICE Filed Nov, 24, 1942 .s Sheets-Sheet 1iTs-il mmvmxs I a I a a I I I I H -8 3 y 8, 1945- v J. o. BISHOP ET AL2,375,341

I BRINELL HARDNESS TESTING. DEVICE Filed Nov. 24, 19-42 3 Sheets-Shget 2W 21/ lmn m INVENTORS y 8, 1945- J. o. BISHOP ET AL I BRINELL,HARDNESSTESTING DEVICE 3 Sheet-sSheet 3 'Filed Navr 24, 1942 INVENTORS PatentedMay 8, 1945 1 sem mnmmss *riistrm'e DEVICE James-O1 Bi'shop,Torrancaand-LloydL. Babcock; Compton, Galifl, assignors to The Nationall Supply Company, Pittsburgh,

ration ofiBennsylvania I Application November 24, 19142;SerialNo.466,782 6Claims. (01; 73-81 This invention relates to a device fordetermining the hardness-of materials and is specifi cally directedtoanimproved machine for making the Brinell hardness test. t

It is the principal object of this i'nvention to provide a device forpressing aBrinelPballjinto the surface of attest-piece, wherein the soleactuating means for the Brinell 'ballj consists of a gravity actuatedweight. j

Another object of this invention is to provide an, actuating device forpressing a Brinell lball into the surface of a test-piece under anaccurately known load. f

Other objects and advantages will'appear, hereinafter.

Figure 1 is a sectional elevation ofa preferred embodiment of myinvention. Figure 2is similar to Figure l but showing the parts inoperative loaded position. Figure 3 is a'plan view partly. in sectionshowing details of the lifting device for the weight member and theelectrical'control forthe apparatus. Figure 4 is avplan view sh'oW-'Pa., a. .corpm relative 'to the column l4i'and, as shown', ma'y- 28.which l are carried. by" the arm- I 5 and operate ing a detailof the camtracKLTFi Quie 5 is a side elevation of the cam track'shown in'Fi'gure4';

Referring to the drawings, a base plate 4; Ihas a central'aperture Zforthe reception of the lower end'of a stationary column or post 3?; Theupper end'of the p0st'3" carries a circular 'plate' 4'provided with acentral opening 5'.

A v block's has a p jecting boss! on its o e Side whichifits looselywithin the opening 5: Atest piecellds adapted to rest upon the Vibl'ock6; or'upon the plate 4-in the absence of the V' blocktl A large annularweight 9 encircles aportion of the post 3' and is supported on a liftingmecha' nismgenerallyidentified as ID. This mechanism is mounted belowthe annular weight 9 and en;-

closed'within a rim H secured' to the base plate I. Secured rigidly tothe upper surface of the annular weight 9 as by means of'bolt's I2; isa' plate l3 which hasa welded'connection to a rigid 001111111114.Slid'ably' mountedionthis column is a horizontally projecting arm "I 5"which; carries an adjusting mechanism generally designated IS; Themechanism l fi'includes atthreacle'd member H provided'with alongitudinally extending keyway l8." A key l'9"carried by. the arm l5 VI1. Whenthe handwheel 22 is turned the memher I! is caused to travelvertically relative to the arm [5. If desired, a further adjustabledevice may be provided for mounting the arm I5 in longitudinal s1ots29formedlin the. column; A key 30 may-be provided :to operate in a keyway,

31 formed on the external surfacejof theoolumn I4. s

' The annular wei ht 9, column. l4,,arm l5 and adjustable mechanism-1i 6forms as weight nember which is adapted to operate as a single unit; Thecolumn l4- and arm ISQIandLthe connection'fbe-.

tween the plate I3 and' the column ll are made sufiiciently rigid toprovide adequatefstiffness and substantiallyv prevent distortion whenthe. weight member is allowed ball2l.

The. lifting mechanism Hi includes a lower-race. plate 32'having ara'ceway3'3in whicha series off ball's 34'operateQ 'Afcam ring..'35having a.sim-. ilar raceway 36' issupported on the balls-Bland isprovided. with a bushing]? for reception-pf the po'st;3 On thecjamring35is provided any annular cam. track L38Tonwhich three equallyspaced rollers 39 are adaptedetooperate. A worm v wheel "is secured tothejplate .-35ja nd -is adapted tobeudriven b'y a worm gear 41;, Thegear 4|. is

driven by an electric motor.floperatingthrough reduction'gearin 43. [Thecam track 38.1 is proe thes rcllers are each mountedron individualshafts s wrca'rriedon spaced depending fingers 4-! secured on a spider.48. The spider'48'is adapted 'for' f ree verticalslidingmovementrelativelto the postv 3 I andi'is keyed asshown at 49 tospr'event rotation relative to the post3. Mounted on the spider 48Iis,alr'ace plate- 50A provided with araceway; 5|

inwhich-a series of iballsiloperate. An upper race plate 53-has acompanion raceway 54 also adapted to cooperate'with the'seriesofballs-52. It will be understood from this description-that whentthe rollers39: ride on the high, portions =44 of the; cam track 3 8 ,thatithespider. 48 supports the annular weight 9bymeansof the-balls 52;; 4

4 In operation, a test specimen 8: is placed'inlthe V block 6, oruponthe plate 4 in the absence. .of v block 6, andthe,operatorinotshowniijturns the handwheel 22- towbring the Brinelllball 2]into contact with the test-piece 8. The operator then s startsthemotorlfl which turns the cam: ring;35

and causes thevv rollers 39' i to. ride "from .the;high portions; 44-on; the com :to; thelow: portions '45; This action causes the race plate50 and the balls 52 to dropaway from the upper race plate 53 as The nut2.1 carriesflateral trunnions to rest solely onithe Brine ll v V asse s1v shown in Figure 2. In the position as shown Figure Ztheentire weightof theannular weight 9 and its.associated',,parts l4, 1I5and i6. issupe: ported solely on the Brinell ball 2|, as indicated by arrows 60and 6| There is no contact between; 5,

the annular weight 9 and the post 3 since it will; be apparent thatclearance is'provided between the post 3 and the bore 55 in the member9. I This;

Y suspended assembly, that is,:,the assembly consisting of the annularweight-9; column l4, arm. I 10 and adjusting device [6 rests only on theball 2| and has not other physical contact with any other,

part of the machine. assembly is made to weigh exactly 3000 kilogramswhich is the standard weight commercially used In practice thissuspended in connection with .the standard'Brinell ball of onecentimeter diameter. One ormore bored holes 62 are preferably providedin the annular weight 9 in order to counterbalance the off-ceni ter loadof the column l4 and arm 15. The 2 amount of material removed by meansof such holes 62 is made to'equaliz'e-theunsymmetricali load imposed bythe column I4 and arm l5, and

the result is that when thezentire .weight of the suspended assembly isallowed to rest on theyg5 Brinell'ball 2| that no swinging movement ofthe weight occurs; In other words, the weight of materialremoved by theholes 62 serves to establish the center of gravity of the suspendedassembly:

on a vertical line passing through the center of the Brinell ball 2 l. 4v I A control switch 56 is provided for starting the" motor 42. Anauxiliary switch 51 is provided and: is arranged to be actuated by'meansof any one of three pins 58' mounted on the worm wheel 40,

When the switch 56 isinitially actuated the mo tor 42 turns the wormwheel through an angle sufficient to cause the rollers 39 to ride fromthe} high parts 44 of the camtrack 38 through the low parts 45 and backagain to the high parts 44; and 40 when'the latter position is "reachedas shown in Figure 3' one of-pins 58 strikes the actuating arm 59controlling the auxiliary, switch 51 thereby interrupting iflow ofcurrent to the motor 42.:

The 'speed offrotation of they Worm wheel 49 is' 45.

such that the rollers 39 travel on the low parts 45 of the cam track38for a sufiicie'nt time to allow the'Brinell ball 2| to sink into thetest spec-; imen 8 to the point where no further movement takes place.This insures that the Brinell ball 2| 1 has been in contact with'thetest specimen 8 for an adequate length of time; When the rollers 39 fagain ride up on to the high parts 44 of the cam track 38 the pressurebetween the Brinell ball 2| and the'test piece 8 is'relieved.,Themotor-42i55 automatically stops at this point as has been describedabove. The, operator then turns the handwheel' 22 topermit removal ofthe test-piece 8. As is well known in the art, the Brinell hardnessnumber is then obtained by measuring the 60 diameterof the indentationmade by the Brinell ball 2|.

Having fully described our invention we claim: 1 l. Ina device of theclass described the combination of a stationary member adapted t supporta test-piece, a weight member provided with; a contact element,-saidweight member encircling" the stationary supporting member, meansforlraising and. lowering the weigh t member as a unit relative to thestationary member,- 'said:70-

means acting to permit the contact'element'to; rest'on the test-pieceand actas the-solesupport j for the entire mass of the weight member; a3

2. In a device of the class described, the combination of'a stationaryVertical post adapted to support a test-piece, an, annularweightencircling a portion of the stationary post,'a contact ele- ;,mentsecured relative to said annular weight in co-axial position, means forlowering the annular weight to bring the contact element and test pieceintoengagemennwhereupon the annular weight is freely' suspended upon thecontact element.

, 3. In a Brinell hardness testing device, the combination of astationary vertical post adapted to support a test-piece, an actuatingmember ineluding an annular weight encircling a portion of thestationarypost but having clearance therewith, an element mounted on said memberand provided with 'a Brinell'balL'said element being adjustable relativeto said annular weight in order to bring the Brinell ball into contactwith l the test-piece, lifting; means adapted to move' the actuatingmember in a direction axially of i v the stationary post, said liftingmeans'being mov-f able' to an inoperative position to permit the,Brinell ball to support. the entire mass of the actuating member uponthe test-piece' 4i In a Brinell hardness testing device, the

combin atiton of a stationary verticalpost adapted to support atest-piece, an'annular weight ena circling a portion of the stationarypost, retractable supporting means for the annular weight, a Brinellball secured relative to said annular weight in coj-axial position,means for adjusting the ver tical position of the Brinell ball relativetothe annular weight .to bring the Brinell ball into pressure contactwith the test-piece, and means for,

retracting the weight supporting means when said ball is in pressurecontact with the test specimenfwhereby the annular weight may be freelysuspended solely upon the Brinell ball. I a 5."In a- Brinell hardnesstesting device, the combination of a'stationary member adapted tosupportla test-piece, a Weight member, a Brinell ball on the weightmember and adapted to contact the test-piece, li ftingand lowering meansfor the weight member including a circular cam track encircling thestationary member, roller elements I operativelyinterposed, between saidcam track j .and said weight member'for normally supporting said weightmember in inoperative position and means for causing rotation of the camtrack whereby the weight member may be raised or lowered, said rotationin one direction being adapted to lower the weight member and permit theentire mass of the weight member being suspended solely on theBrinellball. V

6; In a device for determining the hardness of a test specimen, acontact element, means to support the test "specimen including a columnpositioned in substantial vertical, alignment with a said contactelement, means for pressing the contact element partiallyintothe'surface of the test specimen, a weight member surrounding saidsupporting" colunm,;means'operative1y connecting the j weight member andthe contact element, means for raising and lowering said weight mem beras a unit relative to the supporting column, 7 said weight member andthe means operatively' connecting the weight member and thecontact'element acting under the influence of gravity comprising the-soleactuating force for the con tact element. s

' JAMES'O. BISHOP.

new L. BABc'ocK.

